The field of the present invention relates to supportive catheters for use in advancing wire guides across a lesion.
Wire guides are commonly used during angioplasties to pass through narrow passages in the body so that larger catheters and other devices may be advanced through an intraluminal passage along an already established path. Specifically, during an angioplasty, the wire guide is used to cross the portion of the intraluminal passage which is partially or completely occluded by a lesion. However, when the open passage through the lesion is extremely small or completely occluded, it can be difficult for the wire guide to cross the lesion. Furthermore, because wire guides are typically flexible to accommodate curvatures in the vasculature, they often fail to cross the lesion due to the tip of the wire guide being deflected away from the lesion or due to the body of the wire guide kinking in response to longitudinal force being exerted on the wire guide by the operator. To prevent this, support catheters are commonly used to brace the wire guide within the intraluminal passage. The support catheter is advanced over the wire guide as close as possible to the lesion. The wire guide is then advanced in an attempt to cross the lesion. However, although the support catheter prevents kinking of the wire guide, the body of the support catheter frequently bends, flexes, or kinks in response to the force being exerted by the wire guide. This movement of the support catheter makes it more likely that the wire guide will deflect off the lesion or miss a narrow opening which might exist to cross the lesion. It is desirable that a support catheter provide additional support to the wire guide to prevent the tendency of the support catheter, when under stress, to bend, flex, or kink.
The process of attempting to cross a difficult lesion as described above can become time consuming. Because angioplasties are performed under fluoroscopy, it is desirable to conduct the procedure as quickly as possible to minimize the amount of radiation to which the patient is exposed. Additionally, if the wire guide cannot be advanced across the lesion, the angioplasty cannot be performed, and more invasive alternative procedures must be used instead. More invasive procedures pose greater risk of harm to the patient and require longer recovery times.